<template>
  <div id="app">
    <div
      ref="customerService"
      class="customer-service"
      @touchstart="touchstartHandle('customerService', $event)"
      @touchmove="touchmoveHandle('customerService', $event)"
    >
      <span class="iconfont">&#xe6f6;</span>
    </div>
    <router-view />
  </div>
</template>
<script>
export default {
  name: "",
  components: {},
  props: [],
  data() {
    return {
      touch: {
        initialPosition: {},
        movePostion: {},
      },
      element: {
        initialPosition: {},
        movePostion: {},
      },
    };
  },
  computed: {},
  watch: {},
  created() {},
  mounted() {},
  methods: {
    touchstartHandle(refName, e) {
      // console.log(e)
      // 触摸开始
      let touchTarget = e.targetTouches[0];
      // 记录触摸点的坐标（初始位置）
      this.touch.initialPosition = {
        x: touchTarget.clientX,
        y: touchTarget.clientY,
      };
      // 记录需要移动的元素坐标（初始位置）
      this.element.initialPosition = {
        x: this.$refs[refName].offsetLeft,
        y: this.$refs[refName].offsetTop,
      };
    },
    touchmoveHandle(refName, e) {
      e.preventDefault();
      let touchTarget = e.targetTouches[0];
      // 根据初始touch位置计算移动距离:元素移动位置=元素初始位置+(光标移动后的位置-光标点击时的初始位置)
      let X =
        this.element.initialPosition.x +
        (touchTarget.clientX - this.touch.initialPosition.x);
      let Y =
        this.element.initialPosition.y +
        (touchTarget.clientY - this.touch.initialPosition.y);
      // 限制可移动距离，不超出可视区域
      let maxWidth = innerWidth - this.$refs[refName].offsetWidth;
      let maxHeight = innerHeight - this.$refs[refName].offsetHeight;
      X = X <= 0 ? 0 : X >= maxWidth ? maxWidth : X;
      Y = Y <= 0 ? 0 : Y >= maxHeight ? maxHeight : Y;
      // console.log(X,Y)

      // 移动元素
      this.$refs[refName].style.left = X + "px";
      this.$refs[refName].style.top = Y + "px";
    },
  },
};
</script>
<style lang="scss">
@import "./assets/icon/iconfont.css";
* {
  margin: 0;
  padding: 0;
  list-style: none;
  box-sizing: border-box;
}
html,
body {
  width: 100%;
  height: 100%;
}
#nav {
  padding: 0;
  margin: 0;
}
#app {
  position: relative;
}
.customer-service {
  position:fixed;
  height: 60px;
  width: 60px;
  border-radius: 50%;
  z-index: 999;
  color: #fff;
  font-size: 24px;
  background: rgb(0, 122, 255);
  text-align: center;
  line-height: 60px;
}
</style>
